Oatmeal has for many years been a staple of the human diet due to its health benefits. For example, numerous studies have shown that eating oatmeal on a daily basis can help lower blood cholesterol, reduce risk of heart disease, promote healthy blood flows as well as maintain healthy blood pressure levels. Additionally, oatmeal has a high content of complex carbohydrates and fibers, which facilitates slow digestion and stable blood-glucose levels.
Avenanthramides are antioxidants uniquely found in oats. Since their first isolation in the 1980's, more than 30 congeners have been characterized and the most abundant avenanthramides in oats are 2p, 2f and 2c. These polyphenols demonstrate potent antioxidant, anti-inflammatory and anti-atherosclerotic properties, and may be beneficial to people with chronic inflammatory diseases, allergy and cardiovascular disease. Beyond the food industry, avenanthramides' benefits have also been well documented. Tranilast, an analogue of avenanthramides, has been approved for treating inflammation-related disease and the skin care product Aveeno™ is based on the proven benefits of avenanthramides.
In order to achieve beneficial effects on human health, avenanthramides must be ingested in a sufficient amount. In a 1999 Tufts University study, avenanthramides were confirmed to be bioavailable and remain bioactive in humans after ingestion. After 60 or 120 mg consumption, the maximum concentrations of total plasma avenanthramide were 168 and 560 nM, respectively. A more recent study performed by the University of Minnesota showed that consumption of avenanthramides at doses as low as 0.4 or 9.2 mg/day for 8 weeks increased plasma total antioxidant activity and had dose-response effects on several antioxidant and anti-inflammatory parameters. These effects are probably due to the accumulation and high concentration of avenanthramides in different tissues and organs.
Avenanthramide content in oat grains varies based on cultivars and food processing methods. For example, heat treatment generally reduces avenanthramide 2f, 2c, and more profoundly 2p. The processing methods that increase avenanthramide content are of great importance to help people reach health benefits through regular consumption of oat products.
Nuclear factor-kappa B (NF-κB) is a family of eukaryotic nuclear transcription factors that regulate the transcription of DNA and are involved in the activation of genes related to inflammatory and immune responses. The regulation of the inflammatory response by NF-κB occurs via the enhancement of the expression of genes encoding proinflammatory cytokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-6, and interleukin (IL)-1β. Activation of NF-κB leads to inflammation that in turn is involved in the pathogenesis of many diseases, such as asthma, rheumatoid arthritis, and inflammatory bowel disease and is at least partially responsible for diseases such as atherosclerosis and Alzheimer's disease. Suppression of NF-κB, a regulator of the immune response to infection, is key in limiting the proliferation of cancer cells and reducing the level of inflammation. Studies have shown that avenanthramides inhibit NF-κB activation.
With today's hectic lifestyle, consumers are demanding convenience, such as portability and ease of preparation. Consumers desire oatmeal from a variety of food sources including beverages, and convenience foods such as bars, cookies, crackers, smoothies, and the like.
It is desired to prepare a whole oat product that has sufficient soluble fiber to meet the FDA threshold necessary to justify a health claim. For example, a whole oat product must have 0.75 g soluble beta-glucan fiber per serving of food. To prepare an oat beverage that contains at least 0.75 g soluble oat fiber per serving (about 18 g of whole grain oats), highly soluble oat flour must be used. Traditionally, highly soluble flour is prepared using enzymes such as α-amylase. The enzyme-treated oat flour is then drum or spray dried. This method takes place in at least two steps and is traditionally expensive and produces the soluble oat flour in low rates. For example, a slurry batch is prepared of flour (oat) and water (70-90% moisture content). Enzyme(s) are then added to the slurry and held at optimum enzyme reaction conditions followed by enzyme deactivation process. The slurry is then transferred into either a spray or drum drier.
A need exists in the field for oat flour that is highly dispersible in liquid or semisolid media, maintains its standard of identity as whole grain and is rich in antioxidants.